////////////////////////////////////////////////////////////////////////////////////////
//
//  Copyright 2017 Alexander Stukowski
//
//  This file is part of OVITO (Open Visualization Tool).
//
//  OVITO is free software; you can redistribute it and/or modify it either under the
//  terms of the GNU General Public License version 3 as published by the Free Software
//  Foundation (the "GPL") or, at your option, under the terms of the MIT License.
//  If you do not alter this notice, a recipient may use your version of this
//  file under either the GPL or the MIT License.
//
//  You should have received a copy of the GPL along with this program in a
//  file LICENSE.GPL.txt.  You should have received a copy of the MIT License along
//  with this program in a file LICENSE.MIT.txt
//
//  This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND,
//  either express or implied. See the GPL or the MIT License for the specific language
//  governing rights and limitations.
//
////////////////////////////////////////////////////////////////////////////////////////

#include <ovito/core/Core.h>
#include <ovito/core/dataset/pipeline/PipelineFlowState.h>
#include <ovito/core/dataset/DataSet.h>
#include <ovito/core/oo/CloneHelper.h>

namespace Ovito {

/******************************************************************************
* Returns the data collection of this pipeline state after making sure it is
* safe to modify it.
******************************************************************************/
DataCollection* PipelineFlowState::mutableData()
{
    if(_data && _data->numberOfStrongReferences() > 1) {
        _data = CloneHelper().cloneObject(_data.get(), false);
		OVITO_ASSERT(_data->numberOfStrongReferences() == 1);
    }
    return _data.get();
}

}	// End of namespace
